1. Field of the Invention
The invention relates to an image processing apparatus and an image processing method, and in particular to a structure that performs color correction processing to color signals included in input image data.
2. Description of the Related Art
It is known in the prior art, as a color correction process, to perform a gamma correction process, for example, that corrects image data according to print density characteristics or color reproduction characteristics, which are exerted by a printing apparatus. As for these types of correction processes, it is possible to obtain corrected image data by performing an interpolation calculation to values obtained by referencing a lookup table.
An example of the above kind of color correction is disclosed in Japanese Patent Laid-Open No. 2007-208619. More specifically, Japanese Patent Laid-Open No. 2007-208619 discloses performing gradation correction using an expanded lookup table that is made by interpolating between two grid points of an underlying base lookup table.
However, in the conventional correction process that uses the above described lookup tables and the interpolation calculation, there may be a case where the intended specified value can not be obtained as an output value. For example, in the case of performing a gamma correction process while using a 1D lookup table and an interpolation calculation for table value, there are a case where it is intended to output a specified value for a maximum gradation value or a maximum density value of input image data. However, in the conventional processes, with respect to the maximum gradation value, an interpolation calculation is performed to table values based on the maximum gradation value, and a result is output. For this reason, there may be a case that the result of the interpolation does not match the specified value, and the intended specified value can not be obtained as an output value. As a result, for example, unnecessary dots of a color printing material such as ink are formed at white areas where dots are not to be printed, and dot missing is caused on a solid-image region where dots of the color printing material should be formed on the entire area.